We ran into this at least one other time, but I'm having no luck tracking it down.

Basically their is a context menu plugin.xml contribution for a menu manager that's trying to determine if the action is applicable BEFORE the core plugin (ModelEditorImpl & ModelerCore) are actually loaded.

Thanks for the reply Barry. Let me know if you need more info about how to repro this error (basically just follow the steps outlined in the JIRA). I'm using a 32 bit ubuntu VM on a windows host machine and am able to recreate the problem every time.